Gervais Lake

Gervais Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Gervais Lake reaches 41 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 235 acres and 3.3 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Ramsey County's 49 graded lakes, Gervais Lake ranks 29 — below the local median, though not at the bottom.

Gervais Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at Gervais Lake, one of 14 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. Ice-out has been logged at Gervais Lake more than two dozen times, putting the median around Apr 3 — a useful baseline for tracking climate trends. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.